Continuation of lighting system

ABSTRACT

An overhead lighting system is formed by embedding a plurality of light elements within a support structure, such as a ceiling panel of a suspended ceiling. The light elements are preferably ultra-bright light emitting diodes (LEDs). The LEDs are mounted in the ceiling panel so that the light emitted from each LED projects from a first surface of the ceiling panel and down into a respective space.

RELATED APPLICATIONS

[0001] The present application is a continuation of Ser. No. 09/821,436,which was filed on Mar. 29, 2001, by Bendrix L. Bailey for a LIGHTINGSYSTEM, now patent.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to lighting systems and, morespecifically, to a lighting system in which a plurality of lightelements are embedded in or mounted to a support structure.

[0004] 2. Background Information

[0005] Many commercial spaces, such as offices, have suspended ceilingsthat are spaced from a permanent ceiling. A suspended ceiling allowsutility items, such as pipes, ductwork, electrical wiring, computercabling, etc. to be placed in the space between the permanent ceilingand the suspended ceiling. The utility items are thus kept out of sightfrom the occupant of the office, and yet remain relatively accessiblefor repairs and other work. The suspended ceiling typically includes agrid or frame that is formed from a plurality of interlocking, invertedmetal “T” beams or rails. The grid may be hung from the permanentceiling by a series of cables or wires that are anchored to thepermanent ceiling. The “T” beams or rails of the grid define a pluralityof open, rectangular-shaped spaces into which ceiling panels or tilesare placed.

[0006] To provide overhead lighting in spaces having suspended ceilings,light fixtures are installed in place of several ceiling panels. Forexample, for every 15 or so ceiling panels, a light fixture isinstalled. The light fixtures typically mount flush to the suspendedceiling, and replace an entire ceiling panel. The light fixtures includeone or more fluorescent tubes to provide the light, and are similarlysupported by the suspended ceiling frame. A diffuser or grid may also beprovided so as to diffuse the light being emitted by the fluorescenttube(s). Electrical power is provided to the light fixtures by runningelectrical lines to them. In particular, electrical lines are run from ajunction or distribution box to the light fixture through the spacebetween the permanent and suspended ceilings.

[0007] Although fluorescent tubes typically require less power thanincandescent bulbs for roughly the same luminescence, they still can berelatively expensive to operate. For example, fluorescent tubes have alimited life. Thus, the tubes must be frequently checked and replaced.Their power consumption, moreover, is not insignificant. As a result,the use of fluorescent tube-based light fixtures contributes to the highoperating costs faced by many businesses and other organizations whorent and own office and manufacturing facilities.

[0008] Accordingly, a need exists for a lighting system that isespecially suited to overhead lighting applications, and yet is lesscostly to install and/or operate than light fixtures having fluorescenttubes.

SUMMARY OF THE INVENTION

[0009] Briefly, the invention is directed to a lighting system in whicha plurality of light elements are embedded within or mounted to asupport structure. In accordance with a preferred embodiment, thesupport structure is a ceiling panel for use with a suspended ceiling,and the light elements are ultra-bright light emitting diodes (LEDs).Such LEDs have lower power requirements and longer lives thanfluorescent tubes. The panel is generally rectangular in shape anddefines first and second opposing surfaces. The LEDs are mounted in theceiling panel so that the light emitted by each LED projects from thefirst surface of the ceiling panel. Thus, upon installation of the panelin the grid of the suspended ceiling, the light generated by the LEDsshines down from the panel and into the corresponding space. The panelmay have a plurality of conical or concave recesses formed in its firstsurface for receiving the LEDs. The recesses may have a reflectivesurface to increase the amount of light being delivered into the room. Aconductive strip that may be attached to the second surface of the panelpreferably contains electrical leads that wire the LEDs into a seriescircuit. A direct current (DC) voltage is applied to the conductivestrip, thereby powering the LEDs embedded within the panel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The invention description below refers to the accompanyingdrawings, of which:

[0011]FIG. 1 is a perspective view of a room having a suspended ceilingin accordance with the present invention;

[0012]FIG. 2 is a cross-sectional view of a ceiling panel illustratingthe light element in detail;

[0013]FIG. 3 is an isometric view of a ceiling panel illustrating itsfirst or lower surface;

[0014]FIG. 4 is a plan view of the ceiling panel of FIG. 3 illustratingits second or upper surface;

[0015]FIG. 5A is a partial isometric view of a grid element and a railconnector;

[0016]FIG. 5B is an end view of the rail connector of FIG. 5A;

[0017]FIG. 6 is a partial isometric view of a ceiling panel having alight element in accordance with another embodiment of the presentinvention;

[0018]FIG. 7 is an electrical wiring diagram of the ceiling panel ofFIG. 6;

[0019]FIG. 8 is a highly schematic representation of a duty cycle foroperating the light element of FIG. 6; and

[0020]FIGS. 9 and 10 are isometric views of other embodiments of thelight elements and support structures of the present invention.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

[0021]FIG. 1 is a perspective view of an office or room 100 illustratingan exemplary embodiment of the present invention. The room 100 includesa floor 102, two opposing side walls 104 and 106, a back wall 108 and apermanent ceiling 110. Spaced from the permanent ceiling 110 is asuspended ceiling 112. The suspended ceiling 112 is made up of aplurality of ceiling panels 114 held in place by a metal grid or frame116. As described below, the grid 116 consists of a plurality ofinverted “T” rails. The rails are interconnected with each other to formrectangular-shaped openings into which the ceiling panels 114 areplaced. The metal grid 116 hangs from the permanent ceiling 110 by aplurality of cables 118. Each cable 118 has a first end that is anchoredto the permanent ceiling 110 and a second end that is attached to themetal grid 116.

[0022] Further description of the present invention is now made withreference to FIGS. 2-5. FIG. 2 is a cross-sectional view of a ceilingpanel 114 illustrating a light element 124 embedded therein, FIG. 3 isan isometric view of the lower surface of ceiling panel 114, FIG. 4 is aplan view of the upper surface of ceiling panel 114, FIG. 5A is apartial isometric view of a grid element, and FIG. 5B is an end view ofa rail connector. Embedded within the ceiling panel 114 are a pluralityof light elements 124. The light elements 124 are preferablyultra-bright, light emitting diodes (LEDs) configured to emit “white”light. Each light element 124, which is best shown in FIG. 2, includesat least one semiconductor diode or chip 126 for emitting light, aprotective dome 128, and a base 130. The diode or chip 126 generates thelight and is enclosed within the protective dome 128, which ispreferably formed from clear, unbreakable plastic.

[0023] As shown in FIGS. 3 and 4, each ceiling panel 114 issubstantially rectangular in shape and defines a first or lower surface134 (FIG. 3) and a second or upper surface 136 (FIG. 4). Within theceiling panel 114, the light elements 124 may be arranged in aplurality, e.g., three, equally spaced rows that run substantiallyparallel to the longer sides of the panel 114. The light elements 124are preferably embedded within the panel 114 such that the light theyemit is directed away from the nominal plane defined by the first orlower surface 134. In the illustrative embodiment, a plurality ofrecesses 138 (FIG. 2) are preferably formed in the ceiling panel 114 inorder to receive the light elements 124. Each recess 138 may be conicalor concave-shaped, and the light element 124 may be mounted at or nearthe apex or top of the recess 138. The recesses 138 may be made from areflective, conical or concave-shaped insert. Alternatively, the surfaceof the recess 138 may be coated or painted with a reflective material sothat light from the respective light element 124 is reflected away fromthe panel 114.

[0024] Suitable LEDs for use with the present invention are commerciallyavailable from The LED Light Company of North Las Vegas, Nev. Such LEDshave a luminous intensity of approximately 1560 to 5600 mcd, and drawapproximately 120 milliwatts (mW) of power. Those skilled in the artwill recognize that LEDs typically emit light of a single color. Oneknown method for the light element 124 to produce white light is to havea highly efficient blue diode combined with a phosphors that gives of abroadband “white” glow when excited by the blue light from the diode.Other methods are also possible.

[0025] Disposed along the second or upper surface 136 of the ceilingpanel 114 is a conductive strip 140 (FIG. 4). The conductive strip 140preferably has a plurality of segments or legs 141 a-c, such that eachsegment or leg 141 a-c corresponds to a row of light elements 124embedded within the respective panel 114. Each segment 141 a-c formingthe strip 140 may be ribbon-shaped, and each segment 141 a-c may bejoined together at a first end 137. The segments 141 a-c preferablyextend a substantial length of the panel 114. Disposed within theconductive strip 140 is at least one wire for electrically connectingthe light elements 124. Preferably, each segment or leg 141 a-c has itsown power and its own ground wire. More specifically, segment 141 a hasa power wire 132 a and a ground wire 132 b. Segment 141 b has a powerwire 133 a and a ground wire 133 b. Segment 141 c has a power wire 135 aand a ground wire 135 b. The power and ground wires, e.g., wires 132a-b, for each segment, e.g., segment 141 a, are used to wire the lightelements 124 for the respective segment into a single series circuit.One or more current limiting resistors 142 a-c may be added in series tothe electrical circuit of each segment or leg 141 a-c.

[0026] In the illustrative embodiment, the conductive strip 140 isformed from a flexible material, such as plastic, rubber, etc., and isstrong enough to support the light elements 124. That is, the lightelements 124 may be fastened or otherwise attached to the conductivestrip 140 in a “built-in” manner. The conductive strip 140 may furtherinclude an adhesive backing for use in attaching the strip 140 to thesecond or upper surface 136 of the ceiling panel 114. Alternatively, thestrip 140 may be bonded or glued to the ceiling panel 114. Otherfastening arrangements or methods could also be utilized.

[0027] Grid 116 is preferably formed from a plurality of interlocking,inverted metal “T” rails 146 (FIG. 5A). Rails 146 include an uprightsegment 146 a and a base 146 b. The rails 146 are hung from thepermanent ceiling 110 by cables 118, and are preferably joined togetherso as to define a plurality of open, rectangular-shaped spaces intowhich the panels 114 may be inserted and supported. Panels 114 arepreferably placed in the spaces defined by the rails 146 so that thepanels' first or lower surfaces 134 face the floor 102 of the room 100.In this way, the light emitted by the light elements 124 is directed ina generally downward direction, thereby illuminating the room 100.

[0028] Those skilled in the art will recognize that there are numerousways to provide or deliver electrical power to the light elements 124embedded within the ceiling panels 114.

[0029] In a preferred embodiment, a direct current (DC) voltagesufficient to power the light elements 124 embedded within the panels114 is provided in one or more insulated channels which are manufacturedinto the metal rails 146 of the grid. Disposed along the rails 146 andthe panels 114, moreover, are corresponding pairs of electricalconnectors configured for mating engagement with each other. Morespecifically, attached to rail 146 are a plurality of spaced-apart railconnectors 148 (FIG. 5A). The rail connectors 148 may be generallyserpentine or L-shaped as best shown in FIG. 5B and have a hook portion145 configured so that the connector 148 may be “hooked” over theupright segment 146 a of the rail 146, thereby securing the railconnector 148 to the rail 146. Mounted to a first segment 148 a of therail connector 148 are a pair of spaced-apart, electrically conductivebands 147 a-b that are preferably arcuate or curved so as to provide aspring or bias action relative to the first segment 148 a of the railconnector 148.

[0030] Coupled to the rail connector 148 is a wire 143 carrying twoconductors 143 a-b (FIG. 5B). Each conductor 143 a-b of the wire 143 iselectrically connected to a respective one of the bands 147 a-b.

[0031] Coupled to the conductive strip 140, which, as described above,is itself attached to the upper or second surface 136 of the panel 114,is at least one panel connector 150 (FIGS. 3 and 4). The panel connector150 may also be L-shaped and arranged so that a first segment 150 a(FIG. 3) extends or hangs over an edge 114 a of the panel 114. The panelconnector 150 also includes a pair of spaced-apart, electricallyconductive bands 151 a-b that may be flat or curved. The power wire 132a, 133 a, 135 a for each segment 141 a-c is coupled to one band 151 b,while the ground wires 132 b, 133 b, 135 b are coupled to the other band151 a.

[0032] To provide electrical power to the light elements 124 within apanel 114, a voltage is applied across the pair of bands 151 a-b of thepanel connector 150. When the panel 114 is installed in an opening inthe grid 116, each band 151 a-b of the panel connector 150 mate inelectrical engagement with a respective band 147 a-b of a rail connector148 associated with that panel 114. A positive 24 volts DC is thenapplied to one conductor 143 b of wire 143, while the other conductor143 a is electrically grounded. By virtue of the mating engagementbetween the rail and panel connectors 148, 150, a voltage drop existsacross each light element 124 embedded in the panel 114. Assuming thereare six light elements 124 coupled to each strip 140 (18 light elementsin all), each light element 124 would receive approximately 4 volts DC,which is sufficient power to operate the LED. The size of the currentlimiting resistor 142, moreover, is preferably selected so that therequisite current flows through the series circuit, e.g., approximately18 milliamps (mA).

[0033] One or more conventional DC power supplies (not shown) may beused to provide the voltage to first conductor 143 b. The DC powersupply may be mounted in the space between the permanent and suspendedceilings 110, 112. The ground conductor 143 a may be electricallyconnected to a building ground in a conventional manner. Each panel maybe powered in a similar manner. That is, one or more rail connectors 148are positioned along rails 146 to mate with the one or more panelconnectors 150 associated with each panel 114.

[0034] It should be understood that more than one panel connector may beprovided on each panel 114.

[0035] Other power delivery arrangements can also be provided. Forexample, DC power and ground may be provided through the metal rails 146themselves rather than wires 143. More specifically, attached to theupright portion 146 a of each rail 146 may be one or more rail bands.The rail bands may be arcuate or curved so as to provide a spring orbias action relative to the respective rail 146. Coupled to each of theelectrically conductive strips 140 that run along the tops of panels 114are two or more panel bands. The panel bands associated with a givenstrip 140 preferably extend over opposing edges 114 a, 114 b of thepanel 114.

[0036] When a panel 114 is installed in an opening in the grid 116, thepanel bands mate with respective rail bands. As a result a circuit isdefined between a first rail, the conductive strips 140, and a secondrail. To provide electrical power to the light elements, a voltage isapplied across each pair of adjacent rails of the frame 116. Forexample, a positive 24 volts DC is applied to a first (i.e., power)rail, while a second (i.e., ground) rail is electrically grounded. Thatis, the rails alternate power-ground-power-ground, etc. By virtue of themating engagement between the rail and panel bands, a voltage dropexists across the conductive strip and thus across the respective lightelements 124.

[0037] Cross rails (not shown) which extend perpendicularly to and arejoined to the alternating power and ground rails must be electricallyinsulated from either the power and/or the ground rails to preventshort-circuiting the power supply to the light elements 124. Anysuitable insulating material may be used. The bottom exposed portion ofthe T-rails may be insulated to reduce the risk of shock.

[0038] It should be understood that if more light elements are desired,additional segments 141 could be added to the conductive strip 140.Similarly, if fewer light elements are required, one or more segments141 could be removed. Furthermore, if light elements having differentpower requirements are used, other voltages and currents may be applied.

[0039] It should be understood that the conductive strip 140 mayalternatively be formed from an electrically conductive material such ascopper, and leads (not shown) from the light elements 124 may beattached to strip 140 by crimping, soldering, etc.

[0040] Those skilled in the art will also recognize that many ways existto control the light elements 124 embedded within the panels 114. In apreferred embodiment, the light elements may be controlled on aroom-by-room and/or a panel-by-panel basis. That is, all of the lightelements in a given room or all of the light elements of a given panelcan be controlled so as to be either “on” or “off”. This may beaccomplished by providing one or more light switches (not shown) withinthe room 100, each switch being configured to govern one or more panels114. Alternatively, remotely operable switches may be disposed proximateto the panels 114 and operated by the occupant using a remote controldevice. By selectively turning different panels 114 on and off withinspace 100, the occupant can cause the desired lighting to be provided.For example, all of the panels that are located above the occupant'sdesk or work area may be activated while other panels are turned off.Indeed, the lighting density (i.e., the number of light elements 124embedded within a single panel 114) may be varied depending on theparticular lighting requirements in different areas of the room 100.

[0041] Those skilled in the art will recognize that panels 114 may be ofvarious sizes and shapes.

[0042] As shown, with the present invention, overhead lighting isprovided by a large number of small light elements that are dispersedpreferably across the entire ceiling. The individual light emitted fromall of these small light elements combine to provide sufficient overalllight within the space to perform many tasks, such as reading andworking at a computer terminal. This is in contrast to conventionaloverhead lighting designs in which just a few large lights fixtures areused to illuminate the space. By their nature, these large lightfixtures, even with the addition of diffusers, can produce an unevenlight.

[0043] Colored Light Elements

[0044] Although the present invention has been described as using“white” LEDs, colored LEDs may also be advantageously used. For example,the light elements 124 embedded within a single panel 114 may havedifferent colors and/or be controlled so as to emit light of differentcolors. In addition, a single light element could be configured toselectively emit light of different colors. Different lighting effectscan be achieved by varying the color of the light elements 124 embeddedwithin the panels 114 installed in space 100. Indeed, by varying theintensity of red, blue and green LED chips, light of nearly any desiredcolor, including “white,” can be created.

[0045]FIG. 6 is a partial isometric view of a panel 114 having amultiple diode, light element 160. Light element 160 has a plurality,e.g., three, semiconductor diodes or chips 162, 164, 166 each configuredto emit light of a different color, e.g., red, blue and green. Thediodes 162, 164, 166 are enclosed inside an outer, protective dome 168,and are mounted to a base 170. Associated with each diode 162, 164, 166is a wire 132 a, 132 b, 132 c. A separate electrically controlled switch172, 174, 176, is disposed along each wire 132 a-c. Mounted to the upperor second surface 136 of panel 114 is a programmable microcontroller 184that is operably coupled to each switch 172, 174, 176. As describedherein, the microcontroller 184 is configured to control, at relativelyhigh frequencies, the power flowing through each individual wire 132 a-cby opening and closing switches 172, 174, 176. Specifically, themicrocontroller 184 is used to pulse (i.e., apply power intermittentlyto) each of the diodes 162, 164, 166 individually such that the “light”resulting from the combined output of diodes 162, 164, 166 has a desiredcolor.

[0046] In fact, white light is actually a combination of light of eachvisible color (e.g., red, orange, yellow, green, blue, etc.). Thus, inaddition to the embodiment described above, a “white” LED can also beformed by installing red, blue and green semiconductor diodes within asingle bulb or dome, and constantly running all three diodes. The lightfrom each of these “colored” diodes combines to form a “white” light. Bypulsing the diodes at different frequencies, however, one color (e.g.,blue) can be emphasized over the others, thereby producing abluish-white light.

[0047] An infra-red (IR) detector 185 may be operatively coupled to themicro-processor 184. The IR detector 185 is configured to receivecommand signals from a remote IR transmitter (not shown). By operatingthis remote, an occupant of the space can control the color of lightemitted by light element 160.

[0048]FIG. 7 is an electrical wiring diagram 700 for a panel 114 havinga plurality of light elements 160, each having a plurality ofsemiconductor diodes or chips 162, 164, 166. As shown, eachsemiconductor diode having the same color characteristics, e.g., diode162 (“red”), of the light elements 160 is preferably wired in a seriescircuit to a power source 702 and a ground 704. As described above, anelectrical switch 172, 174, 176 is disposed in each of these seriescircuits to open or close electrical power from source 702. Each seriescircuit also includes a current limiting resistor 706, 708, 710 sizedsuch that a desired current flows through the respective circuit.

[0049] In the illustrative embodiment, the power source 702 and groundare also connected to the microprocessor 184 so as to provide electricalpower thereto.

[0050]FIG. 8 is a highly schematic illustration of a duty cycle used 186used by the microcontroller 184 to run the multi-diode light element 160so that it provides a bluish-white light. A first plot 190 shows thevoltage (v) applied to the green diode 166 (FIG. 5) as a function oftime (t). A second plot 192 shows the voltage (v) applied to the bluediode 164 as a function of time (t), and a third plot 164 shows thevoltage (v) applied to the red diode 162 as a function of time (t). Asshown, the voltage applied to any diode at any instance of time t iseither 4 volts or 0 volts. That is, the respective diode is either “on”or it is “off”. The length of time that the diodes are kept on or offrelative to each other, however, is varied. In the duty cycle of FIG. 6,for example, both the green and red diodes 166, 162 are pulsed in suchas manner that they are “on” for one unit of time T and then off for oneunit of time T and so on. The blue diode 164, however, is pulseddifferently. In particular, the blue diode 164 is “on” for two units oftime T and then off for one unit of time T and so on. Thus, for a givenlength of time, the blue diode 164 is “on” more often than the red orgreen diodes 162, 164. The result is perceived as a bluish-white lightbeing emitted by the light element 160 (FIG. 5). Preferably, theselected time T is small enough so that the occupant of the space 100does not notice any flicker from the light elements.

[0051] The microcontroller 184 can be made programmable so that theoccupant of the space 100 may adjust the “color” of the light beingemitted by the light elements 160 as desired. Indeed, a joystick ormouse could be provided for controlling the “color” produced by thelight element 160. Moving the joystick or mouse in a first direction,for example, could emphasize the blue diode, while moving them in secondand third directions could emphasize the red and green diodes,respectively.

[0052] Suitable microcontrollers for use with the present invention arecommercially available from Intel Corp. of Santa Clara, Calif. and TexasInstruments Inc. of Dallas, Tex., among others. Suitable electricalswitches, which can be formed from field effect transistors (FETs), arealso commercially available.

[0053] It should be understood that the light elements may be embeddedin other support structures besides ceiling panels. For example, thelight elements 124 could be embedded within a flexible material thatcould be used as wallpaper. Again, the light elements and their wiringwould be “built-in” the flexible material. In this case, the flexiblematerial containing the light elements could be uncoiled from a roll andapplied to a wall or ceiling of a selected space. A voltage could beapplied across the wiring in order to power the light elements.

[0054] Furthermore, the light elements 124 may be embedded within theceiling panel 114 either at the time the panel is manufactured orafterwards. Those skilled in the art will recognize that there are manydifferent ways of embedding or mounting the light elements to ceilingpanels either at the time the panels are manufactured or afterwards.

[0055]FIG. 9 is an isometric view of a series of light elements 202mounted to a thin, flexible support medium 204. The flexible supportmedium 204 defines a first or lower surface 206 from which the lightelements 202 preferably project. The support medium 204 may include anadhesive backing (not shown) on a second or upper surface 208. Runningthrough or on the support medium 204 is a wire 210 connecting each ofthe light elements 202 in series. At a first end 210 a of the wire is aconnector 212. The support medium 204 with the light elements 202 ispreferably attached to the ceiling panel 114 by using the adhesivebacking. Alternatively, it may be bonded or glued thereto. Otherfastening arrangements or means could also be utilized. The supportmedium 204 is preferably fastened to the ceiling panel 114 so that thefirst end 210 a of wire 210 wraps around the edge 114 a of the ceilingpanel 114. Connector 212 is thus disposed in the space defined betweenthe permanent ceiling and the suspended ceiling. A power line having aconnector designed to mate with connector 212 is preferably used tosupply power to the light elements 202. Another pair of matingconnectors (not shown) are preferably used to couple a ground wire tothe other end of wire 210, thereby completing the series circuit.

[0056] The flexible, ribbon-shaped support medium 204 may be formed froma woven or non-woven material. Exemplary materials include cloth, paper,plastic, metal, fiberglass, carbon, etc. The light elements 202 may bebonded or glued to the support medium 204 or attached by otherarrangements.

[0057] It should be understood that the support medium 204 and lightelements 202 may be used with and/or attached to other buildingcomponents besides ceiling panels. For example, the support medium 204may be mounted directly to a permanent ceiling in a room or space whichdoes not have a suspended ceiling. The support medium 204 mayalternatively be mounted to a wall.

[0058]FIG. 10 is an isometric view of a possible although generally lessadvantageous embodiment of embedding or mounting light elements to aceiling panel. Here, a plurality of light elements 220 are mountedwithin respective inserts 222. The inserts 222 preferably include asubstantially flat, circular disk 224. Attached to a first face of thedisk 224 is a generally cylindrical sleeve 226 within which a respectivelight element 220 is received. A plurality of wire segments 228interconnect the light elements 220 in series. A series of spaced-apartholes 230 preferably extend through the ceiling panel 114. Holes 230 aresized and spaced to receive light elements 220. More specifically, holes230 are sized and shaped so that the sleeves 226, but not the disks 224fit into the holes 230. The disks 224 thus rest on the second or uppersurface 136 of the panel 114 keeping the light elements 220 from fallingout when the panel 114 is installed in the suspended ceiling 112 (FIG.1).

[0059] Alternatively, the sleeve 226 could be concave or conical asopposed to cylindrically shaped, and could include a reflective coating.The sleeve 226 could even be omitted and a cone-shaped or concave hole230 could be formed in the panel 114 to receive the light elements 220.

[0060] The foregoing description has been directed to specificembodiments of the invention. It will be apparent, however, that othervariations and modifications may be made to the described embodiments,with the attainment of some or all of their advantages. For example,instead of LEDs, the light elements could be formed from laser diodesand/or light emitting polymers (LEPs), among other possible lightelements. Therefore, it is an object of the appended claims to cover allsuch variations and modifications as come within the true spirit andscope of the invention.

What is claimed is:
 1. A lighting system comprising: a support structuredefining a first surface; and a plurality of light elements mounted tothe support structure, each light element having at least one lightemitting diode (LED), wherein the light elements are arranged so thatthe light emitted by the LEDs projects primarily away from the firstsurface of the support structure.
 2. The lighting system of claim 1further comprising an electrical power delivery system coupled to thelight elements.
 3. The lighting system of claim 2 wherein the electricalpower delivery system includes one or more wires connecting the LEDs inseries.
 4. The lighting system of claim 3 wherein the light elements areat least partially embedded in the support structure.
 5. The lightingsystem of claim 4 wherein the support structure includes a plurality ofrecesses formed in the first surface, each recess configured to receivea corresponding light element.
 6. The lighting system of claim 5 whereinthe recesses are cone-shaped and one or more of the recesses includes areflector configured to reflect light emitted by the light elements awayfrom the primary surface.
 7. The lighting system of claim 6 wherein thesupport structure is a ceiling panel configured for use with a suspendedceiling.
 8. The lighting system of claim 7 wherein the ceiling panel isconfigured to be supported by a plurality of rails of a suspendedceiling, the ceiling panel includes a first edge, each conductive stripincludes at least one connector disposed at the first edge, and therails include at least one receptacle configured for mating engagementwith the connector disposed at the first edge of the ceiling panel fortransmitting electrical power from the rails to the conductive strip. 9.The lighting system of claim 8 wherein each conductive strip includesone or more resistors for controlling the electrical power delivered tothe light elements coupled to the conductive strip.
 10. The lightingsystem of claim 9 wherein the light elements employ white LEDs.